The Underachievers, a young rap duo from Brooklyn, released two mixtapes of hazy, conversational, word-dense rap music last year, and both of them ended up in the Mixtape Of The Week column. And now the duo is getting ready to release The Cellar Door: Terminus Ut Exordium, their first proper album. We’ve posted a few of its tracks — “Chrysalis,” “Felicity,” “Metropolis” — and now you can stream the whole album at NPR.